Import DEFAULT_CONTRAST only where the tests use it

The calibration commit imported it at module level, where only the
test module reads it; the build warned and clippy's -D warnings
refuses that.

core/dr-pipeline/src/camera_raw.rs

@@ -19,7 +19,7 @@
 //! shader to it.
 
 use crate::ops::camera_profile::{mul, working_prophoto};
-use crate::view::{DEFAULT_CONTRAST, DEFAULT_WHITE, REFERENCE_CONTRAST, SCENE_GREY};
+use crate::view::{DEFAULT_WHITE, REFERENCE_CONTRAST, SCENE_GREY};
 
 /// The input scale for a white point: 1 at the default, so sensor white is
 /// display white as in the SDK's reference; each stop of `white` above it halves the
@@ -100,6 +100,7 @@ fn camera_raw_tone(c: vec3<f32>, scale: f32, power: f32, grey: f32) -> vec3<f32>
 #[cfg(test)]
 mod tests {
     use super::*;
+    use crate::view::DEFAULT_CONTRAST;
     use dr_types::tone::{evaluate, ACR3_DEFAULT};
 
     fn identity() -> Vec<f32> {